Plural section distillation column with top feed



April 6, 1948. v wqF. BARTHEL 2,438,988

PLURAL SECTION DISTILLATION COLUMN. wITH TOP FEED Y Filed Jan. 12, 1945 Patented Apr. 6, 1948 PLURAL SECTION DISTILLATION COLUM WITH TOP FEED william F. Barthel, college Peek, Ma., signer te the United States of America as represented by A the Secretary of Agriculture Application January 182, 1945, Serial No. 572,503 claims. (ci. zoe-154) (Granted under the act of March 3, 1883, as amended April 30, 1928; 370 0. G. 757) This application is made under the act of March 3, 1883, as amended `by the act of April 30, 1928, and the invention herein` described, if patented, may be manufactured and used by or for the Government of the United States of America for governmental purposes Without the payment to me of any royalty thereon.

This invention relates to a distillation apparatus, and in particular to an apparatus which will produce rapid evaporation of liquids and solvents.

In the usual procedure for the concentrations of solutions or the removal of liquid solvents, the original solution is heated in a vessel either at atmospheric pressure or reduced pressure and the volatile portion vaporized by boiling. In such cases, the thickness of the liquid layer is such that the rate of evaporation is slow, and as the` solution becomes more concentrated, the rate of evaporation becomes yet slower.v Thus, a long period of heating is required. The solute must be stable to the heat treatment necessary to remove the solvent, if the procedure is to be em ployed without harm to the solute. Many matel rials, however, decompose during such a proin the single figure of the accompanying draw- In the drawing, the principal element of the apparatus is an upwardly extending tubular member or column II heated by means of a surround--` ing heat jacket I2 provided with a heating uuid` inlet I3 and an outlet I4 in a conventional manner. The inner surface of the column II, over which the liquid :being distilled flows as a layer, is provided with laterally extending corrugations,` preferably formed by constructing the column; itself as a. connected row of hollow spheres in the manner illustrated. There is no communication" between the heating fluid and the interior of the column. The structure thus provides means for heating the column independently of the temperature and flow over the internal surface of the column of the liquid being distilled.

'I'he solution or distillation liquid enters the column at the top from a supply tank I 5 and the rate of ow may be regulated by an adjustable 'aid in accomplishing an even distribution of the liquid on the internal surface of the column. This type of valve operates automatically when arranged in the manner shown, since gas pressures develop under the ball I9 in excess of that above, due to upward movement of the gas,` causing the ball to bob on its seat and intermittently release liquid entrapped above it.

The upper section Il of the column acts as a boiler and the lower section I8 as a stripper of the more concentrated liquid. More sections may, of course, be provided.' f

As the liquid flows downwardly, the disnuate is removed and the residue is finally deposited in the receiver 2 I.

The distillate is carried through pipes 22 and 23 connected to the upper ends of the sections Il and I8, respectively, these pipes communicating with an expansion chamber 24. Any droplets of` the liquid which may be carried over with the Idistillatesettle to the bottom of the expansion.-

chamber and ow back to the column through the pipe 23 which is connected to the lower portion of the expansion chamber.

From the expansion chamber. the distillate gas passes through pipe 25 to a conventional condenser l2l from whence the condensate is recovered through pipe 21. Low pressure distillation is accomplished by evacuating through the condenser in a conventional manner.

As an example of use of the apparatus, a solution of 10 percent total pyrethrins in nitromethane was passed through the apparatus under a 40 mm. vacuum. The upper and lower sectionsV were heated with steam at C. The nitromethane evaporated at this low ,temperature without decomposing the pyrethrins, giving a 98 percent concentration of the pyrethrins in the take approximately 10 times as long to remove cut-off valve I6 in the line connecting the supply 55 the nitromethane in a conventional still and the the liquid descends, it`

casacca 3 pyrethrins would peratures of the conventional still for the entire time required for distillation.

Having thus described the invention, what is claimed is:

1. Distillation` apparatusA comprising an up'--- ubieetea to the higher tem-v wardly extending tubular column, means for introducing distillation liquid into the upper end oi' the column. said column being so constructed that a film of the liquid is spread over its internal surface as it descends the column and being divided into an upper section and a lower hsection with a valve between the sections which traps opens to allow the liquid to flow into the -lower section, and means for heating the column indepedently of the temperature a'nd flow over-the internal surface of the column of the liquid being distilled.

2. The 'apparatus of claim 1, characterized -in that the valve operates automatically.

valve between the sections which traps liquid in the upper section and intermittently opens to allow the liquid to ow into the lower section, an

expansion chamber, pipes leading from the upper ends of the 'sections for carrying distillate gases into the expansion chamber, one of said pipes being connected to the lower portion of said ex' pansion chamber to carry any liquid which settles in the expansion chamber back into the column,

vand means for heatingthe column independently l v vliquid in the upper section and intermittently into an upper section and a lower section with a of the temperature and iiow over the internal surface ofthe coiuinnof the liquid being distilled.

5. Distillatin apparatus comprising an upwardly extending tubular column, means for introducing distillation liquid into the upper end of the column. said column being so constructed that a 111m of the liquid is' spread over its internal urface as vit descends the column and being 'tdiv'ided into an upper section and a lower section with a valve between the sections which traps liquid in the upper 'section and intermittently opens to allow the liquid to iiow into the lower section, and a jacket provided with a heating iluid inlet and a heating-huid outlet surrounding the lcolumn with no communication between the heating iluid lwithin the -jacket and the interior o'f-the column.

WILLIAM F. BARTHEL.

REFERENCES CITED The following references are of record lin the fue f'thls Ptent! STATES PATENTS OTHER REFERENCES th Catalogue of Laboratory Apparatus Supplies, of Eimer and Amend, New York. a copy of which may be found in Division 59, pages 308, 309, and 310. I Y i 

